Benzoxazines, thermosetting resins comprised thereof, and methods for use thereof

Abstract

In accordance with the present invention, there are provided novel benzoxazine compounds and thermosetting resin compositions prepared therefrom. Invention compositions are particularly useful for increasing adhesion at interfaces within microelectronic packages. Invention benzoxazines are useful for the preparation of invention compositions with properties which are associated with increased adhesion at interfaces, such as, for example, low shrinkage on cure and low coefficient of thermal expansion (CTE). In another aspect of the invention, there are provided die-attach pastes having increased interfacial adhesion. Invention die-attach pastes include benzoxazine-containing thermosetting resin compositions. In further aspects of the invention, there are provided methods for enhancing adhesive strength of thermosetting resin compositions and methods for enhancing adhesion of a substrate bound to a metallic surface by a thermosetting resin composition.

1. A thermosetting resin composition for adhering materials with dissimiliar coefficients or thermal expansion, consisting essentially of:
 a) a benzoxazine compound in liquid form at room temperature, 
 b) one or more thermoset compounds selected from the group consisting of epoxy, cyanate ester, maleimide, acrylate, methacrylate, vinyl ether, styrenic, vinyl ester, propargyl ether, diallylamide, aromatic acetylene, benzocyclobutene, thiolenes, maleate, oxazoline, and itaconate, 
 c) optionally, one or more anti-oxidants, bleed control agents, fillers, diluents, coupling agents, adhesion promoters, flexibilizers, dyes and pigments, and 
 d) a cure initiator. 
 
     
     
       2. A method for enhancing adhesive strength of a thermosetting resin composition between materials with dissimiliar coefficients of thermal expansion, said method consisting essentially of the step of:
 incorporating an effective amount of a benzoxazine compound in liquid form at room temperature into a composition comprising one or more thermoset compounds selected from the group consisting of epoxy, cyanate ester, maleimide, acrylate, methacrylate, vinyl ether, styrenic, vinyl ester, propargyl ether, diallylamide, aromatic acetylene, benzocyclobutene, thiolenes, maleate, oxazoline, and itaconate; optionally, one or more anti-oxidants, bleed control agents, fillers, diluents, coupling agents, adhesion promoters, flexibilizers, dyes and pigments, and a cure initiator. 
 
     
     
       3. A method according to  claim 2 , wherein one of the materials with dissimiliar coefficients of thermal expansion has a metallic surface to which the thermosetting resin composition is adhered. 
     
     
       4. A method according to  claim 3 , wherein said metallic surface is copper. 
     
     
       5. A method for adhesively attaching a first substrate to a second substrate, said method comprising the steps of
 providing the first substrate, 
 providing the second substrate, 
 providing a thermosetting resin composition according to  claim 2  positioned between said first and second substrates and curing the composition therebetween. 
 
     
     
       6. A method according to  claim 5 , wherein said first substrate is a semiconductor die and said second substrate is circuit board. 
     
     
       7. A method according to  claim 5 , wherein said first substrate is a semiconductor die and said second substrate has a metallic surface, which is a lead frame. 
     
     
       8. A method according to  claim 7 , wherein said lead frame is a copper lead frame. 
     
     
       9. A composition according to  claim 1 , wherein said maleimide is in liquid form. 
     
     
       10. A composition according to  claim 1 , wherein said filler is conductive. 
     
     
       11. A composition according to  claim 1 , wherein said filler is electrically conductive. 
     
     
       12. A composition according to  claim 1 , wherein said filler is thermally conductive. 
     
     
       13. A composition according to  claim 1 , wherein said maleimide has the structure: 
       
         
           
           
               
               
           
         
       
       wherein:
 m is 1-3, 
 each R is independently hydrogen or lower alkyl, and 
 X is a straight chain alkyl, alkylene, or alkylene oxide, or branched chain alkyl, alkylene or alkylene oxide, optionally containing cyclic moieties as substituents on said alkyl, alkylene or alkylene oxide chain or as part of the backbone of the alkyl, alkylene or alkylene oxide chain.